I want to calculate Leaf Water Conten Index (LWCI) using Landsat or Sentinel data. I found several usefull formulas that use NIR and SWIR bands. But to estimate LWCI I have to have NIR and SWIR reflactance for the fully hydrated leaf and it is a problem. How to measure fully hydrated leaf reflactance or maybe I have to use some constants, but I need reference on them. Can any one help me with that problem? Many thanks!
Hi Leonid,
If you don't mind sharing with us the wavelengths available for you, it will be easier for helping you.
And for the fully hydrated leaf reflectance, you might have on your dataset some time point or location where the crop are in well irrigated condition. In this case, might be use as a reference.
Nicolas
Hi Leonid,
Please find in attached some useful papers that give more explanation about that.
All the best
Kamel
Name- Leaf Water Content Index
Formula- log(1−(NIR−MIDIR))−log(1−(NIR−MIDIR))log(1-(NIR-MIDIR))-log(1-(NIR-MIDIR))
Description- NIR= TM4 MIDIR = TM5
Nicolas Virlet Thank you for your answer. As reference paper I used "Detection of changes in leaf water content using near-and middle-infrared reflectances." by E. Raymond Hunt, Jr. . So formula is known. And as wavelengths for calculation from this paper and on other sources 0.82 µm and 1.6 µm are used. Thus bands 5 and 6 (NIR and SWIR) of Landsat-8 can be used. But on this paper proposed to use constant 0.2 as reflectance for fully hydrated leaf of 1.6 wavelengths. On other sources I also saw 0.11 and also other values. But I can't find how this constants were estimated. Maybe there is some known constants estimated using other satellite sources ( my logic similar to emissivity that can be defined as constant using MODIS data or constant table for common materials and land covers)
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